What does the spray-paint colour on metal stock mean?
Paint on the end of a bar can help you find stock, but its meaning depends on the supplier and product. Start with the applicable supplier chart and stock documentation rather than a generic internet colour legend.
Whose colour system is it?
Edcon describes paint applied to the end of its steel products as grade identification in its own guide. The guide distinguishes steel grade from the paint manufacturer’s Signet code and links a separate size-coding guide. It also recommends checking the product before further work.
Even a supplier’s paint system needs the right chart for the product and purpose. A rack location colour or workshop status colour can have an entirely different local meaning. Do not assume the same colour means the same metal at another supplier.
Source context: Edcon Steel: its steel colour-code guide
A scoped example: Atlas stainless steel
The following five examples come only from the Stainless Steels section of the Atlas Steels national Product Colour Coding Chart, revised 29 March 2021. They are not a universal Australian metal colour standard.
| Grade in this Atlas chart | Colour in this Atlas chart |
|---|---|
| 303 | Light Blue |
| 304 | Lilac |
| 316 | Bottle Green |
| 2205 | Lime |
| 2507 | Violet |
Source context: Atlas Steels national Product Colour Coding Chart, revision 29 March 2021 (PDF)
Paint cannot distinguish every certification
Atlas gives 304L and dual-certified 304/304L the same colour as 304. It gives 316L and dual-certified 316/316L the same colour as 316. The paint alone therefore cannot distinguish these certifications.
The document warns that printed copies are uncontrolled and users must check the latest revision. Confirm the applicable chart with Atlas for the delivery. Bottle Green means 316 in this cited Atlas stainless chart; it does not establish that any green-painted bar is 316.
Source context: Atlas Steels national Product Colour Coding Chart, revision 29 March 2021 (PDF) · Atlas Steels: product colour-chart landing page
Verify identity before allocating stock
Our suggested receiving method is to record supplier, product description, section, dimensions and ordered grade with the delivery or stock tag. Where the job requires heat traceability or certificates, keep those references with the stock record and match the applicable documentation.
Resolve uncertain material with the supplier before assigning it to a job. Faded paint or a loose remnant without a trusted identity needs verification. The charts describe colour systems; they do not certify a random painted offcut or make it suitable for substitution.
Keep identity when the painted end is cut away
Give a retained offcut a durable written label with stock ID, verified material and grade, section, measured usable length, location and required delivery/certificate/heat reference. Keep this internal remnant label separate from the supplier colour chart.
If the workshop also uses colours for status or rack locations, document those local meanings. A cutting calculation allocates length; it does not establish grade, certification or interchangeability. Run incompatible grades and sections as separate plans.
A fictional remnant identification label
Fictional teaching example — static illustrative data, not a customer job, measured saving or calculated app result.
DEMO-R014 | verified 304 stainless | 25 mm round | usable length 780 mm | rack B2 | delivery DEMO-D07.
This illustrates a label format, not a certified or available piece of stock. Real required heat and certificate references must follow the job’s traceability requirements.
Sources and scope
This is a research-based workshop guide. Supplier charts and software documentation apply to their named products and contexts; confirm current details before relying on them.